Holographic microscope

ABSTRACT

The preferred embodiments of the present invention include a holography attachment device that is attachable to a digital imaging device to form a holographic microscope. The holography attachment device includes a chamber having at least one attachment mechanism to facilitate attachment of the chamber to a digital imaging device. The holography attachment device also includes a light source and a sample holder section, which is located between a proximate end and the distal end of the chamber. The light source is configured to radiate light within the chamber. The light passes through the sample holder section and impinges on an imaging sensor of a digital imaging device when the chamber is attached to the digital imaging device. The digital imaging device is capable of recording hologram information related to a sample held by the sample holder in the sample holder section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to holographic microscopy, and morespecifically to a holography attachment device that is attachable to adigital imaging device.

2. Brief Description of Related Art

Holographic microscopy uses holographic imaging to overcome limitationsfound in other forms of microscopy. Holographic microscopy can beimplemented using digital holography techniques to acquire and displaythree-dimensional (3D) information about a sample.

Digital holography has been brought about by rapid advances in digitalimage acquisition technology, where imaging sensors, such as chargecoupled devices (CCDs) and Complimentary Metal Oxide Semiconductor(CMOS) imaging sensors, can acquire digital images with high opticalresolution and sensitivity. Imaging applications that may use digitalholography can include biological microscopy, fluid dynamics, particletracking, and the like.

Holographic imaging is typically implemented as a two-step process. Inthe first step, two-dimensional (2D) image information of one or moreobjects is collected via an imaging sensor. In the second step, the 2Dimaging information must be reconstructed using a reconstructiontechnique to produce a 3D representation of the sample. Thereconstruction technique reconstructs the wavefront at the object usingnumerical evaluation of the Kirchoff-Helmholtz transform.

In recent years, holographic microscopes that allow users to acquireholographic images have been constructed using imaging components (e.g.,imaging sensor and signal processor) and a light source spaced at adistance from, and configured to radiate light towards, the imagingsensor. These units are generally expensive and can be burdensome totransport and use in field applications. Further, these units can onlybe used for a single application (i.e. holographic microscopy). As aresult, a holography attachment device that is attachable to andcompatible with stand alone digital imaging devices is desired.

SUMMARY OF THE INVENTION

The preferred embodiments of the present invention include a holographyattachment device that can be attached to a digital imaging device. Thedigital imaging device can have a body and an imaging sensor disposedtherein to convert light into an electric charge. The holographyattachment device is configured to attach to the digital imaging device,hold a sample, and radiate light through the sample. The light radiatingthrough the sample can impinge on the imaging sensor when the holographyattachment device is attached to the camera body and the imaging sensorcan record a two-dimensional hologram associated with the sample.

In some embodiments, the digital imaging device can convert thetwo-dimensional hologram data to three-dimensional image data using areconstruction technique and can display the three-dimensional image. Inother embodiments, a computing device can be configured to receive thetwo-dimensional hologram data from the digital imaging device and toconvert the two-dimensional hologram data to a three-dimensional imageusing a reconstruction technique.

In the preferred embodiments, the holography attachment device includesa chamber and preferably a light source. The chamber of the holographyattachment device has a proximate end configured to attach to a digitalimaging device, a distal end having a wall, and a sample holder sectionlocated between the proximate end and the distal end. The chamber can beconfigured to attach to digital imaging device, such as a single lensreflex (SLR) digital camera, a digital point-and-shoot camera, or a cellphone-based digital camera. In some embodiments, the chamber can beattachable to the digital imaging device in place of a detachable lensand can be configured to attach to an SLR camera interface. The chambercan substantially prevent light external to the chamber from entering aninternal cavity of the chamber.

The light source is configured to radiate light within the chamber. Thelight source can include a light emitting device, such as a laser diodeor light emitting diode for generating coherent or incoherent light, asingle mode fiber, and a light manipulating device, such as a lens,aperture, collimator, or beam expander. The single mode fiber has aproximate end and a distal end, the proximate end being coupled to thelight emitting device. The light manipulating device can be located inthe path of the light to manipulate the light by, for example, focusingthe light. The single mode fiber can guide light radiating from thelaser diode to the light manipulating device, through which lightexiting the single mode fiber passes. The light radiated in the chamberpasses through the sample holder section and is incident on an imagingsensor of the digital imaging device when the chamber is attached to thedigital imaging device. In some embodiments, the light source can bedisposed on the distal end of the chamber so that the light source isinline with the imaging sensor when the chamber is attached to thedigital imaging device.

The sample holder section is configured to receive a sample. Forexample, the sample holder section can receive at least one of amicroscope slide and a cuvette, both of which can hold a sample. In someembodiments, at least one of the light source and the sample holdersection can be adjusted with respect to the other to increase ordecrease the distance between the light source and the sample holdersection.

In one embodiment hologram data associated with a sample can be observedby attaching a holography attachment device to an off-the-shelf digitalcamera, inserting a sample in the holography attachment device,radiating light through the sample, and recording a two-dimensionalhologram associated with the sample from the light impinging upon theimage sensor. In some embodiments, the holography attachment device canbe attached to the off-the-shelf digital camera by securing theholography attachment device to the off-the-shelf digital camera inplace of the camera lens. In other embodiments, the holographyattachment device can be attached to the off-the-shelf digital camera bysecuring the holography attachment device over a lens of theoff-the-shelf-digital camera. A three-dimensional image can beconstructed from the two-dimensional hologram data, which can then berendered on a display.

The preferred embodiments of the holography attachment device, as wellas other objects, features and advantages of the present invention willbe apparent from the following detailed description, which is to be readin conjunction with the accompanying drawings wherein like referencenumerals in the various figures are utilized to designate likecomponents. The scope of the invention will be pointed out in theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a holography attachment device attachedto a digital imaging device in accordance with a preferred embodiment ofthe present invention;

FIG. 1B depicts a preferred embodiment of a light source of theholography attachment device of FIG. 1A in more detail;

FIG. 1C depicts an exemplary sample holder that can be used with theholography attachment device of FIG. 1A;

FIG. 2 is a side view of a holography attachment device having a powersource attached to a digital imaging device;

FIG. 3 is a side view of a holography attachment device detached from adigital imaging device;

FIG. 4 is a side view of another embodiment of a holography attachmentdevice detached from a digital imaging device;

FIG. 5 is a side view of a holography attachment device suitable for usewith a point-and-shoot digital camera;

FIG. 6A is a perspective view of a holography attachment device suitablefor use with a cell phone-based camera;

FIG. 6B is a perspective view of the holography attachment device ofFIG. 6A attached to a cell-phone having an embedded digital camera;

FIG. 7 is a block diagram illustrating the operation of the holographyattachment device and digital imaging device when the holographyattachment device is attached to the digital imaging device;

FIG. 8A depicts an illustrative hologram of a region acquired by apreferred embodiment of the present invention; and

FIG. 8B depicts the same region reconstructed in several sample planes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention are directed to aholography attachment device that is attachable to a digital imagingdevice, such as a single lens reflex (SLR) digital camera, apoint-and-shoot digital camera, a cell phone based camera, and the like.The holography attachment device can include an attachment mechanism forsecuring the holography attachment device to the digital imaging device.In some embodiments, the attachment mechanism of the holographyattachment device interfaces with an attachment mechanism on the digitalimaging device. The holography attachment device, when attached to thedigital imaging device, allows the digital imaging device to recordtwo-dimensional (2D) hologram information associated with an object,held by the holography attachment device, via an imaging sensor withinthe digital imaging device. The 2D hologram can subsequently be used toconstruct three-dimensional (3D) images. The preferred embodiments ofthe present invention can have a lateral resolution of about 2micrometers or better.

As used herein, “digital imaging device” broadly refers to a device thatis manufactured to capture light and generate digital images, andincludes all commercially or otherwise available off-the-shelf digitalcameras or digital imaging modalities, such as SLR digital cameras,point-and-shoot digital cameras, cell phone-based digital cameras,webcams (internal or external to a computing device), digital camerasintrinsic to personal music devices, cameras based in hand heldcomputers (e.g., personal digital assistants (PDAs)), and the like.

FIG. 1A depicts a perspective view of a holography attachment device 130attached to a digital imaging device 110 (hereinafter “device 110”), theimplementation of which being generally known to those skilled in theart. FIG. 2 depicts a side view of the device 110 with a power unit 200disposed thereon. In the present embodiment (FIGS. 1 and 2), the device110 is a SLR digital camera that includes a camera body 112 with anattachment mechanism 114 that facilitates interfacing the device 110with the holography attachment device 130. The attachment mechanism 114can be a lens mount of the device 110 that can be implemented using aninterface known to those skilled in the art, such as a screw-in type, abayonet type, or a frictionless lock type for securing various SLR lensand/or the holography attachment device 130 thereto. The device 110 caninclude an imaging sensor 116, such as a charge coupled device (CCD)sensor or a Complimentary Metal Oxide Semiconductor (CMOS) imagingsensor, for receiving and converting light into electric charge. Thedevice 110 can also include other electronic components known to thoseskilled in the art for processing the electric charge, such as ananalog-to-digital converter (ADC), a digital signal processor (DSP),storage, and the like. While the present embodiment shows the device 110as a SLR digital camera, those skilled in the art will recognize thatother types of digital imaging devices, such as a point-and-shootdigital camera, a cell phone camera, or other commercially availableoff-the-shelf digital imaging modality can be interfaced with theholography attachment device in accordance with the preferredembodiments of the present invention.

The holography attachment device 130 preferably includes a chamber 132,a light source 140, a sample holder section 154, and an attachmentmechanism 160. The chamber 132 preferably has a cylindricalconfiguration that has a substantially continuous longitudinalcylindrical surface about a center axis 134. A distal end 136 of thechamber 132 has a wall 138. The configuration of the holographyattachment device 130 is preferably formed such that the holographyattachment device 130 substantially prevents light of the surroundingenvironment from entering the internal cavity of the chamber 132 whenthe chamber 132 is attached to the device 110. As an alternative, theattachment need not be cylindrical nor have a substantial longitudinalcylindrical surface if, for example, the sample is inserted into thecamera or imaging device body.

The light source 140 (FIGS. 1A and 1B) can be disposed with respect tothe wall 138 so that the light source 140 radiates light 142 through theinternal cavity of the holography attachment device 130 preferably alongthe center axis 134. The light source 140 can be configured to generatecoherent or incoherent light and preferably includes a light emittingdevice 144, such as a laser diode, a light emitting diode (LED), or thelike. As used herein, “coherent” light refers to in phase, singlewavelength light radiation, such as light that is generated by a laser.For embodiments that are configured to generate incoherent light, theincoherent light can be incoherent monochromatic light radiation, suchas light that is generated by an LED, which is typically spatially andspectrally less coherent than laser radiation. In some embodiments,multiple light emitting devices operating at different wavelengths canbe used for improved axial resolution of phase imaging.

The light source 140 also preferably includes a single mode fiber 146,and a light manipulation device 148, such as Gradient Index (GRIN) orother converging/diverging lenses, a pinhole aperture, collimator, beamexpander, and the like. In a preferred embodiment, the lightmanipulation device 148 is a GRIN lens or pinhole aperture used to focusthe light radiating from the light emitting device 144 to a point fromwhich the light radiates in a fashion approximated by a spherical wave.In an alternative embodiment, the light manipulating device 148 can beconfigured to produce other wavefronts, such as that of a plane waveproduced by a beam expander. In some embodiments, the light source 140can be implemented using the light emitting device 144 without thesingle mode fiber 146 and/or the GRIN lens 148 and a diverging lens orno lens may be used.

The light emitting device 144 is preferably coupled to the single modefiber 146 at a proximate end 150 so that light from the light emittingdevice 144 is guided by the single mode fiber 146. The lightmanipulating device 148, such as a GRIN lens, is located at a distal end152 of the single mode fiber 146 such that light 142 passes through thelight manipulating device 148 and towards the image sensor 116. In oneembodiment, the light manipulating device 148 is a GRIN lens that isconfigured with a radially decreasing gradual refractive index variationso that light passing through the GRIN lens converges upon a focal pointclose to the distal end of the lens. The resulting wavefront is closelyapproximated as a spherical wavefront from the GRIN lens' focal pointwhich illuminates the object and sensor.

Still referring to FIGS. 1A and 2, the sample holder section 154 can beformed in the lateral surface of the chamber 132 and can extend inwardlyand across the internal cavity of the chamber 132 in a direction that issubstantially orthogonal to the center axis 134. The sample holdersection 154 allows objects to be placed between the light source 140 andthe imaging sensor 116 so that when the holography attachment device 130is attached to the device 110 and operating, the light 142 from thelight source 140 preferably passes through and around the object so thatthe light impinges upon the imaging sensor 116, which records 2Dhologram information related to the object. In some embodiments, thelight source 140, the sample, and the imaging sensor 116 are placeinline with each other so that the object and reference wave traversingthe same path. In these embodiments, the sample and the sample holdertypically have a low optical density so that light incident on thesample and the sample holder is not excessively scattered. In otherembodiments, the object wave and the reference wave may not traverse thesame path.

The distance between the light source 140 and the sample holder section154 can be a predetermined distance, or in some embodiments, thelocation of the sample holder section 154 or the light source 140 can beadjusted so that the sample holder section 154 or light source 140 canbe moved closer and/or further away from each other. Likewise, thedistance between the sample holder section 154 and the imaging sensor116 can be a predetermined distance or can be adjustable. In a preferredembodiment, a sample holder 156, such as a microscope slide or acuvette, can be used to hold a sample 158 (e.g. an object) (FIG. 1C).The sample holder 156 can be inserted into the sample holder section sothat the sample can be positioned in the path of the light 142.

The attachment mechanism 160 of the holography attachment device 130 islocated at a proximate end 162 of the holography attachment device 130and is configured to interface with the attachment mechanism 114 of thedevice 110 so that the holography attachment device 130 can be securedto the device 110. The preferred embodiments of the attachment mechanism160 are discussed in more detail below.

In some embodiments, the holography attachment device 130 can include apower source 200 disposed at the distal end 136 (FIG. 2). The powersource 200 can be a battery (rechargeable or disposable) that can beused to power the light source 140. For embodiments that do not includethe power source 200, the light source can be powered by the powersource of the device 110. The overall power requirements of theholography attachment device are minimal and might be supplied by asolar cell or manual generator.

FIG. 3 depicts one embodiment of the attachment mechanisms 114 and 160.In the present embodiment, the attachment mechanisms 114 and 160 havecorresponding threaded sections 302 and 304, respectively. To secure theholography attachment device 130 to the device 110, the holographyattachment device 130 can be attached to the device 110 using thethreaded sections 302 and 304 such that the attachment mechanisms 114and 160 threadingly engage each other. The attachment mechanisms 114 and160 allow for interchangeability of attachment devices. For example, auser can have multiple camera lenses and holography attachment devicessuitable for connecting to the device 110. The user can easily removethe lens and replace it with the holography attachment device 110 sothat the digital camera is converted into a holographic microscope thatcaptures 2D hologram information, which can be processed to generate 3Dimages. Thus, the user can have a single digital imaging device that canbe used for multiple applications. As a result, the user can transform aconventional digital camera into a holographic microscope simply byusing the holography attachment device 130 disclosed herein. As aresult, the cost of holographic microscopy can be reduced and the amountof equipment required to perform multiple imaging applications can bereduced. In addition, the preferred embodiments of the present inventionprovide a low cost route to high resolution microscopy which is easilytransported and applicable under conditions where a conventional lightmicroscope is impractical or impossible.

FIG. 4 depicts another embodiment for implementing correspondingattachment mechanisms 114 and 160. In the present embodiment, theattachment mechanism 114 of the device 110 can include recessed portions402 on the sides of the device 110 for receiving a portion of theattachment mechanism 160 of the holography attachment device 130. Thedevice 110 can have a body 112 that houses the electronic components ofthe device 110, which can include those components typically found in adigital camera, such as an imaging sensor, ADC, DSP, storage, and thelike. In addition, the device 110 can include a lens 404. The lens 404may be a fixed focal point lens, a telescoping lens, compact foldedoptical zoom lens that is typically positioned vertically within thebody and that uses a prism that folds the optical path, or any suitablelens technology. The holography attachment device 130 can fit over thelens area.

The attachment mechanism 160 can include extended clamping sections 406that engage the recessed portions 402 of the device 110 and canlockingly secure the holography attachment device 130 to the device 110.The clamping sections 406 can include a spring mechanism that forces theclamping sections 406 inward towards the center axis 134 of theholography attachment device 130 such that the holography attachmentdevice 130 is secured to the device 110 by the force imposed by thespring mechanism.

FIG. 5 depicts another embodiment of an attachment mechanism 160. In thepresent embodiment, the device 110 represents a digital point-and-shootdigital camera, which can be a cell phone-based digital camera, theimplementation of which is known to those skilled in the art. The device110 can have a body 112 that houses the electronic components of thedevice 110, as discussed above. In addition, the device 110 can includethe lens 404. The holography attachment device 130 can fit over the lensarea. The attachment mechanism 160 can be implemented as straps 502 thatcan be fastened around the body 112 of the device. The straps 502 can betightened around the body 112 to securely attach the holographyattachment device 130 to the device 110. In some embodiments, the strapscan include Velcro®, buckles, tension fasteners, and the like.

The holography attachment device 130 can also include a resilient member504 at the proximate end 162 of the chamber 132 of the holographyattachment device 130. The resilient member 504 preferably conforms tothe perimeter or circumference of the chamber 132 at the proximate end162. The resilient member 504 can be formed from a resilient polymer,such as rubber. When the holography attachment device 130 is attached tothe device 110, the resilient member 504 can be compressed against thebody 112 of the device 110 as the attachment mechanism tightens aroundthe device 110 to ensure that the holography attachment device 130 isfirmly secured to the device 110. The resilient member 504 can alsoprevent the device 110 and the holography attachment device 130 frombeing damaged when the holography attachment device 130 is attached tothe device 110.

FIG. 6A is a perspective view of another embodiment of a holographyattachment device suitable for use with a cell phone-based digitalcamera and FIG. 6B is a perspective view of the holography attachmentdevice attached to the cell phone-based digital camera. In the presentembodiment, the device 110 is a cell phone-based digital camera, theimplementation of which is known to those skilled in the art. The device110 can have a body 112 that houses the electronic components of thedevice 110, as discussed above. In addition, the device 110 can includethe lens, which is embedded in the body 112 so that there is a lens areaon the body 112 through which light can pass. The holography attachmentdevice 130 can fit over the lens area. The attachment mechanism 160 canbe implemented as, for example, clamping mechanisms 602 that can beclamped to the body 112 of the device. The clamping mechanism caninclude a spring mechanism that forces the clamping mechanisms 602inward towards the center axis 134 of the holography attachment device130 so that the holography attachment device 130 can be lockinglysecured to the device 110 by the force imposed by the spring mechanism.

FIG. 7 depicts a block diagram that illustrates the preferred operationof the holography attachment device 130 and the device 110 when they areattached. A sample 702, such as liquid containing microorganisms, can beplaced on or in the sample holder 156, which can be a microscope slideor a cuvette and can be positioned within the sample holder section 154.The light source 140 can be turned so that light 142 radiates from thelight source 140 towards the image sensor 116. The sample 702 ispositioned in the path of the light 142 so that the light 142 passesthrough and around the sample 702 before impinging upon the image sensor116. For embodiments that include a lens, the light 142 passes throughthe lens before impinging upon the image sensor 116.

The light 142 captured by the image sensor 116 is converted intoelectric charge by a matrix of pixels on the image sensor 116. Theelectrical charge is digitized by the ADC 704 to create a digital signalthat corresponds to the light 142 that impinges upon the image sensor116. The ADC 704 passes the digital signal to the DSP 706 for signalprocessing. The DSP 706 can apply digital processing techniques known tothose skilled in the art. After the digital signal is processed it canbe stored in storage 708. The display 710 can be a liquid crystaldisplay (LCD) or other technologies commonly used by digital imagingdevices to display images. The display 710 can be used to allow the userto contemporaneously view information pertaining to exposure of theimage sensor 116 to the light 142. In addition, the display 710 can beused to view information stored in storage 708.

The light 142 captured by the image sensor 116 represents a 2D hologramthat corresponds to the sample 702 through, and around, which the light142 passes. To generate a 3D image of the sample 702, a reconstructionprocess on the 2D hologram is implemented. In a preferred embodiment,numerical reconstruction techniques known to those skilled in the artcan be employed.

In one embodiment, the device 110 can perform the reconstruction processusing the DSP 706 and/or a processor 712. To achieve this, the device110 can be loaded with software (or firmware) that can be stored instorage 708, DSP 706, and/or the processor 712. The DSP 706 and/or theprocessor 712 can generate a 3D image using the digitized signal fromthe ADC 704 such that the 3D reconstructed images can be generated atthe time the image is captured or the DSP 706 and/or the processor 712can generate the 3D image using a 2D hologram stored in storage 708. Forembodiments where the device 110 can generate the 3D image, the 3D imagecan be rendered on the display 710.

In another embodiment, the device 110 can be connected to a computingdevice 720 that can generate a 3D image using a 2D hologram provided bythe device 110. The computing device 720 can be a mainframe, personalcomputer (PC), laptop computer, workstation, handheld device, such as aPDA, or the like. In the present embodiment, the computing device 720includes a central processing unit (CPU) 722 and preferably a displaydevice 724. The display device 724 enables the computing device 720 tocommunicate directly with a user through a visual display. The computingdevice 720 can further include data entry device(s) 726, such as akeyboard, touch screen, and/or mouse.

The computing device 720 can include storage 728 for storing data, suchas trace information, and instructions, such as instruction forexecuting traces and graphical depictions of network configurations. Thestorage 728 can include such technologies as a floppy drive, hard drive,tape drive, Flash drive, optical drive, read only memory (ROM), randomaccess memory (RAM), and the like.

Applications 730, such as applications for reconstructing a 3D imagefrom a 2D hologram, can be resident in the storage 728. The storage 728can be local or remote to the computing device 720 and can include adatabase 740, to which the computing device 720 can connect via acommunications network 750. The computing device 720 includes a networkinterface 732 for communicating over the network 750 to retrieve orstore information in the database 740. The CPU 722 operates to run theapplications 730 in storage 728 by performing instructions therein andstoring data, such as 3D reconstructed images, resulting from theperformed instructions, which may be depicted via the display 724 or byother mechanisms known to those skilled in the art, such as a print outfrom a printer.

FIGS. 8A-B are exemplary 3D images 800 that can be produced using theholography attachment device 130 in combination with the digital imagingdevice. FIG. 8A shows a hologram and FIG. 8B shows several sample planes850 representing several image distances from the image sensor. In thisexample, the distance between the image sensor, the light source, andthe sample holder section remains fixed, while the reconstruction isperformed to form images at various object planes, such as numericalreconstruction using the Kirchoff-Helmholtz transform, which can becalculated via Fresnel, Fraunhofer approximations or a convolutionapproach. Additional approximations simplifying the Kirchoff-Helmholtztransform are possible depending on the experimental configuration. Asample liquid containing microorganisms is held in a glass cuvette andplaced in the sample holder section. In this example, the light sourceis formed using a laser diode with 635 nanometer wavelength coupled to asingle mode fiber, which is coupled to a Gradient Index (GRIN) lens, andthe digital imaging device is a commercially available Canon® DigitalRebel XT SLR camera.

While the preferred embodiments illustrate using in-line holography(i.e. aligning the light source, sample, and image sensor along the sameaxis), those skilled in the art will recognize that other configurationscan be implemented, such as off-axis holography. In off-axis holography,reference and sample waves can traverse separate paths towards the imagesensor. In this embodiment the geometry of the light source, object andimage sensor may be altered. Still, the light passes through and aroundthe object and is incident on the sensor.

The preferred embodiments advantageously allow users to captureholograms of samples using an off-the-shelf, stand-alone digital imagingdevice. Thus, a user can convert a digital imaging device into aholographic microscope so that the digital imaging device can be usedfor multiple applications (e.g., photography and holographicmicroscopy), which provides a flexible inexpensive solution. Thepreferred embodiments reduce the amount of equipment that a user has totransport when the user wishes to perform both photography andholographic microscopy in the field. Further the preferred embodimentsof the present invention can provide a lateral resolution of about 2micrometers or better.

Although preferred embodiments of the present invention have beendescribed herein with reference to the accompanying drawings, it is tobe understood that the invention is not limited to those preciseembodiments and that various other changes and modifications may beaffected herein by one skilled in the art without departing from thescope or spirit of the invention, and that it is intended to claim allsuch changes and modifications that fall within the scope of theinvention.

1. A holography attachment device for a digital imaging devicecomprising: a chamber having a proximate end configured to attach to adigital imaging device, a distal end comprising a wall, and a sampleholder section located between the proximate end and the distal end, thesample holder section being configured to receive a sample, the chamberbeing configured to receive light.
 2. The holography attachment deviceof claim 1, further comprising a light source configured to radiatelight within the chamber, the light passing through the sample holdersection and being incident on an imaging sensor of the digital imagingdevice when the chamber is attached to the digital imaging device, thedigital imaging device being configured to record hologram informationassociated with the sample in the sample holder section.
 3. Theholography attachment device of claim 2, wherein the light sourcecomprises: a light emitting device for radiating light; and a lightmanipulating device located in the path of the light to manipulate thelight prior to the light passing through the sample.
 4. The holographyattachment device of claim 1, wherein the chamber is attachable to thedigital imaging device in place of a detachable lens.
 5. The holographyattachment device of claim 1, wherein the chamber is configured toattach to an SLR camera interface.
 6. The holography attachment deviceof claim 1, wherein the chamber is configured to attach to at least oneof a digital point-and-shoot camera or a cell phone-based camera.
 7. Theholography attachment device of claim 2, wherein the light emittingdevice generates coherent light.
 8. The holography attachment device ofclaim 1, wherein the chamber is configured substantially prevent lightexternal to the chamber from entering an internal cavity of the chamber.9. The holography attachment device of claim 1, wherein the sampleholder section is configured to receive at least one of a microscopeslide and a cuvette.
 10. The holography attachment device of claim 2,wherein the light source is disposed on the distal end of the chamber sothat the light source is inline with the imaging sensor when the chamberis attached to the digital imaging device.
 11. The holography attachmentdevice of claim 1, wherein at least one of the light source and thesample holder section can be adjusted with respect to the other toincrease or decrease the distance between the light source and thesample holder section.
 12. A digital imaging apparatus configured fordigital holography comprising: a digital camera comprising a body and animaging sensor disposed therein to convert light into an electriccharge; and a holography attachment device configured to attach to thebody, the holography attachment device configured to hold a sample andthrough which light is passed, the light radiating through a sample andimpinging on the imaging sensor when the holography attachment device isattached to the camera body, thereby enabling the imaging sensor torecord two-dimensional hologram data associated with the sample.
 13. Thedigital imaging apparatus of claim 12, wherein the digital camera is atleast one of an SLR camera, a point-and-shoot camera, and a cellphone-based camera.
 14. The digital imaging apparatus of claim 12,wherein the digital camera converts the two-dimensional hologram data tothree-dimensional image data using a reconstruction technique.
 15. Thedigital imaging apparatus of claim 14, wherein the digital cameradisplays the three-dimensional image.
 16. The digital imaging apparatusof claim 12, further comprising a computing device, the computing deviceconfigured to receive the two-dimensional hologram data from the digitalcamera and convert the two-dimensional hologram data to athree-dimensional image using a reconstruction technique.
 17. Thedigital imaging apparatus of claim 12, wherein the holography attachmentdevice comprises: a chamber having a proximate end configured to attachto a digital imaging device, a distal end comprising a wall, and asample holder section located between the proximate end and the distalend, the sample holder section being configured to receive a sample; anda light source configured to radiate light within the chamber, the lightpassing through the sample holder section and impinging on the imagingsensor when the chamber is attached to the digital imaging device,thereby enabling the digital imaging device to record holograminformation associated with the sample in the sample holder section. 18.The digital imaging apparatus of claim 17, wherein the light sourcecomprises: a light emitting device to radiate light; and a lightmanipulating device located in the path of the light to manipulate thelight prior to the light passing through the sample holding section. 19.A method of observing hologram data associated with a sample using adigital imaging device comprising: attaching a holography attachmentdevice to the digital imaging device; and recording a two-dimensionalhologram associated with the sample in response to light passing througha sample and impinging upon the image sensor.
 20. The method of claim19, wherein attaching of the holography attachment device comprisessecuring the holography attachment device to the off-the-shelf digitalcamera in place of the lens.
 21. The method of claim 19, whereinattaching the holography attachment device comprises securing theholography attachment device over a lens of the off-the-shelf-digitalcamera.
 22. The method of claim 19, further comprising constructing athree-dimensional image from the two-dimensional hologram data.
 23. Themethod of claim 22, further comprising rendering the three-dimensionalimage on a display.